1. Field of the Invention
The present invention relates to an improved shock-absorbing suspension for a road vehicle, particularly of the heavy-weight type, which suspension combines the features of both air and leaf spring suspensions.
2. Description of the Prior Art
It is known that leaf spring suspensions are particularly well suited to support heavy loads and, at low speed, to give the driver a good perception of the vehicle's behavior through the steering column. However, on rough terrain and/or when meeting pot-holes, the leaf spring suspension has a slow response so that the impact force to which the wheels are subjected is transmitted directly to the vehicle frame and body, jarring them as well as the vehicle's occupants. Such jarring may also damage the vehicle frame, the axle,the suspension as well as the cargo.
Air suspensions, using air-inflated balloons, have been developped for better shock absorption and have been found quite reliable and comfortable. Vehicle drivers complain, however, that they do not provide an adequate perception of the vehicle's behavior.